Traction instrument for closed-loop dental matrix band



9, 1969 B; F. TOFFLEMIRE 3,

TRACTION INSTRUMENT FOR CLOSED-LOOP DENTAL MATRIX BAND Filed April 14,1969 ==l iuim I7 A ar a-11m In INVENTOR.

.BE NJAMIN F'- TOIF'F'LEMIRE AT TORNEY United States Patent O 3,482,315TRACTION INSTRUMENT FOR CLOSED-LOOP DENTAL MATRIX BAND Benjamin F.Totilemire, 41301 Crest Drive, Hemet, Calif. 92343 Filed Apr. 14, 1969,Ser. No. 815,988 Int. Cl. A61c /12 US. Cl. 3263 Claims ABSTRACT OF THEDISCLOSURE A traction instrument for a closed-loop dental matrix bandhaving a transverse bar arranged to be positioned outside of a patientsmouth, with a pair of band-actuating arms extending forwardly from thebar and adapted for insertion into the mouth so as to occupy arelatively small space, the arms being pivotally secured to outerportions of the bar. Slotted beaks are provided at the forward ends ofthe arms for supporting a closedloop matrix band, and a sliding wedge isused for spreading the beaks so as to constrict the loop of the bandaround a patients tooth, the wedge being made to be advanced andretracted by an operating knob and threaded spindle from a positionoutside of the mouth.

BACKGROUND OF THE INVENTION In my United States Patent No. 3,237,307,dated Mar. 1, 1966, for Traction Instrument for a Dental Matrix Band,there is disclosed two pairs of toggle links arranged to provide asubstantially diamond shaped frame and an operating spindle forconstricting a looped dental matrix band around a patients tooth.However, this frame arrangement must be inserted into the mouth of thepatient, which may present discomfort to the patient and is not readilyoperated by the dentist. Moreover, the wide-arch ing frame of thisearlier instrument took up too much operating space within the patientsmouth.

SUMMARY As the cardinal object of this invention, it is proposed toprovide a traction instrument for closed-loop dental matrix band havinga pair of swingable band-actuating arms adapted for insertion into apatients mouth, these arms having slotted beaks for supporting the band,the beaks being movable into contact with one another so as to occupyvery little space in the mouth. These beaks may be spread apart byoperating means disposed outside of the patients mouth and consequentlynot objectionable, and the spreading of the beaks will effectconstricting of the band around the patients tooth.

Moreover, great leverage with very little effort on the part of thedentist is required, giving a controlled, gradual and self-locking pullon the matrix band. This is accomplished by a sliding wedge havingopposite cam edges bearing against confronting surfaces of the arms, thewedge being advanced and retracted by a threaded spindle and operatingknob located exteriorly of the mouth of the patient.

Other objects and advantages will appear as the specification proceeds,and the novel features of the invention will be pointed out in theappended claims.

3,482,315 Patented Dec. 9, 1969 BRIEF DESCRIPTION OF THE DRAWING For abetter understanding of the invention, reference should be made to theaccompanying drawing, forming part of this specification, in which:

FIG. 1 is a top plan view of my traction instrument for closed-loopdental matrix band, with the beaks thereof being shown in substantiallycontacting relation with one another.

FIG. 2 is a side elevational view thereof.

FIG. 3 is a view similar to FIG. 1, but illustrating the beaks as beingspread apart and constricting the matrix band around a patients tooth.

FIG. 4 is an isometric view of one of the band-actuating arms as seenfrom its inner surface.

FIG. 5 is an enlarged transverse sectional view taken along the plane5-5 of FIG. 3.

FIG. 6 is an isometric view of one of the arms provided with a cutter toshear off the band ends after the band is tightened.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to thedrawing in detail, there is shown a traction instrument indicatedgenerally at A which is adapted for supporting and constricting aclosed-loop dental matrix band B around a patients tooth C, as disclosedin FIG. 3. The details of the matrix band are fully shown in mycopending application, Ser. No. 778,092, filed in the United StatesPatent Ofiice on Nov. 22, 1968.

Briefly stated, the matrix band B defines overlapped end portions 10,with a loop 11 adapted to encircle the tooth 'C, and a combined keeperand traction block 12 is used to secure the outer terminal ends of theband together, and a pin or the like 13 extends through the tractionblock to reinforce attachment of the latter to the band ends and preventthe block from being sheared off when force is applied thereagainstduring constricting of the loop 11 about the axial contour of the tooth.

In its structural details, the traction instrument A has a transversebar 14 arranged to be positioned outside of a patients mouth, and a pairof band-actuating arms 15, extend forwardly from the bar and are adaptedfor insertion into the mouth, the rear ends of the arms being pivotallysecured by journal pins 16 to outer portions of the bar 14.

The arms 15 have beaks 17 at their forward ends which are swingabletoward and away from one another when corresponding movements areimparted to the arms. The beaks 17 define slots 18 into which theoverlapped end portions 10 of the looped matrix band B may be inserted,with the band loop 11 projecting from one of the beaks for encirclingthe tooth C, and the other beak being adapted to have the combinedkeeper and traction block 12 butted thereagainst, whereby the loop willbe constricted around the tooth when the beaks are spread apart.

Prior to constricting the loop 11, a band retainingclamp D may be placedover the overlapped band end portions 11 between the proximal beak 17and the loop of the band. This clamp is more fully shown in my UnitedStates Patent No. 3,046,659, dated July 31, 1962. After the band hasbeen properly constricted, the clamp D may be pressed so that it will befirmly anchored to the band ends, and then the traction instrument maybe removed and the prepared cavity 19 in the tooth C may be filled torestore the tooth.

It will be noted that a longitudinally-extending spindle 20 is threadedthrough the bar 14 for turning in either direction by a large knurledoperating knob 21, which is disposed outside of the patients mouth andfreely accessible to the dentist.

A sliding wedge E has the spindle 20 rotatably anchored thereto by a setscrew 22 that enters an annular groove 23 formed in the forward end ofthe spindle (see FIG. This wedge is disposed between the arms 15 anddefines opposite cam edges 24 bearing against confronting surfaces 25 ofthe arms 15. These cam edges are designed to spread the beaks 17 whenthe wedge E is advanced and to permit the beaks to move toward oneanother when the wedge is retracted. In fact, the beaks are removableinto contact with each other upon retracting the wedge.

As clearly shown in FIG. 1, the transverse bar 14 and the arms 15 definea triangular configuration when the beaks 17 are moved into contact withone another, with the apex of the triangle defining a relative smallangle between the beaks. Resilient means F are provided for urging thebeaks toward one another when the wedge E is retracted, and this is theloading position for inserting the matrix band B into the slots 18.

Referring now to FIGS. 3, 4 and 5, it will be seen that the confrontingsurfaces 25 of the arms 15 are fashioned with longitudinally-extendingcam grooves 26 into which the opposite cam edges 24 of the wedge Eextend and are guided, with these grooves holding the wedge againstrotation when the spindle 20 is turned, whereby the wedge is restrictedto rectilineal movements.

The opposite cam edges 24 of the wedge E substantially taper to a point27 at their forward ends to thus facilitate the initial spreading of thebeaks 17 when the wedge is advanced. Moreover, these opposite cam edgesdefine outwardly-bulged segments 28 arranged to spread the beaks 17further apart when the wedge continues to advance. The wedge has aninitial slower caming action and a subsequently faster camming action,the latter being due to the outwardly-bulged segments 28.

As shown in FIGS. 1 and 3, the confronting surfaces 25 of the arms 15 inback of the grooves 26 are provided with concave notches 29 into whichthe outwardly-bulged segments 28 may be accommodated when the wedge E isretracted and the beaks 17 are brought together.

The resilient means F previously mentioned is provided by achannel-shaped leaf spring defining a web 30 and a pair of side flanges31, the web 30 being disposed in back of the transverse bar 14 andhaving an opening 32 for passage of the spindle 20 therethrough, theflanges 31 projecting forwardly of the pivots or pins 16 and yieldinglyurge the arms 15 toward one another at their beak ends. Each side flange31 is provided with an inturned finger 33 fitting into a notch 34 in theouter surface of the adjacent arm 15.

The transverse bar has a U-shaped bracket 35 fixed thereto andprojecting rearwardly therefrom to provide support for the rear part ofthe spindle 20 (see FIGS. 1, 2 and 3).

The quadrant arch of the teeth is indicated at G in FIG. 3 from which itwill be clear that the bar 14 and operating knob 21 are disposed outsideof the patients mouth.

Each of the arms 15 may be provided with a cutter H to shear off theband ends adjacent to the clamp D after the band has been tightened.Each cutter H has a cutting slot 36 registerable with a slot 18 in thebeak 17, the cutter being jonrnalled by pin 37 to the beak on the outersurface of the latter. The handle 38 may be raised to effect theshearing action.

I claim 1. In a traction instrument for closed-loop dental matrix band:

(a) a transverse bar arranged to be positioned outside of a patientsmouth;

(b) a pair of band-actuating arms extending forwardly from the bar andadapted for insertion into the mouth, the rear ends of the arms beingpivotally secured to outer portions of the bar;

(c) the arms having beaks at the forward ends which are swingable towardand away from one another when corresponding movements are imparted tothe arms;

(d) the beaks defining slots into which overlapped end portions of alooped matrix band may be inserted, with the band loop projecting fromone of the beaks for encircling a tooth, and the other beak beingadapted to have a combined keeper and traction block secured .to theband ends butted thereagainst, whereby the loop will be constrictedaround the tooth when the beaks are spread apart;

(e) a longitudinally-extending spindle threaded through the bar forturning in either direction;

(f) a sliding wedge having the spindle rotatably anchored thereto andbeing disposed between the arms, the wedge defining opposite cam edgesbearing against confronting surfaces of the arms, and the cam edgesbeing designed to spread the beaks when the wedge is advanced and topermit the beaks to move toward one another when the wedge is retracted.

2. The traction instrument for closed-loop dental matrix band, as setforth in claim 1;

(g) and in which the beaks are movable into contact with one anotherwhen the wedge is retracted.

3. The traction instrument for closed-loop dental matrix band, as setforth in claim 2;

(h) and in which the transverse bar and the arms define a triangularconfiguration when the beaks are moved into contact with one another,with the apex of the triangle defining a relative small angel betweenthe beaks.

4. The traction instrument for closed-loop dental matrix band, as setforth in claim 1;

(g) and in which resilient means are provided for urging the beakstoward one another when the wedge is retracted.

5. The traction instrument for closed-loop dental matrix band, as setforth in claim 1;

' (g) and in which the confronting surfaces of the arms are fashionedwith longitudinally-extending cam grooves into which the opposite camedges of the wedge extend and are guided, with the grooves holding thewedge against rotation when the spindle is turned, whereby the wedge isrestricted to rectilineal movements.

6. The traction instrument for closed-loop dental matrix band, as setforth in claim 5;

(h) and in which the opposite cam edges of the wedge substantially taperto a point at the forward ends thereof to thus facilitate initialspreading of the beaks when the wedge is advanced.

7. The traction instrument for closed-loop dental matrix band, as setforth in claim 6;

(i) and in which the opposite cam edges of the wedge defineoutwardly-bulged segments arranged to spread the beaks further apartwhen the wedge continues to advance.

8. The traction instrument for closed-loop dental matrix band, as setforth in claim 7;

(j) and in which the confronting surfaces of the arms in back of thegrooves are provided with concave notches into which theoutwardly-bulged segments may be accommodated when the wedge isretracted and the beaks are brought together.

9. The traction instrument for closed-loop dental matrix band, as setforth in claim 1;

(g) and in which a channel-shaped leaf spring is provided and defining aweb and a pair of side flanges, the web being disposed in back of thetransverse bar and having an opening for passage of the spindletherethrough, the flanges projecting forwardly of the pivots between thebar and the arms and yieldingly urging the latter to swing toward oneanother at their beak ends.

10. The traction instrument for a closed-loop dental matrix band, as setforth in claim 9;

References Cited UNITED STATES PATENTS ROBERT PESHOCK,

Tofllemire 32-63 Thurman 3263 Tofflemire 32-63 Primary Examiner

